---
title: "A light rod of length \\(L\\) is attached to a frictionless pivot at one end. A small object of mass \\(M\\) is fixed to the rod at a distance \\(d\\) from the pivot, where \\(d < L\\). A constant force of magnitude \\(F\\) is applied to the free end of the rod, and the force is always maintained in a direction perpendicular to the rod. The rod and object are initially at rest. What is the magnitude of the angular acceleration \\(\\alpha\\) of the rod-object system immediately after the force is applied?"
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url: "https://nerd-notes.com/ubq/113096/"
date_modified: "2026-05-05T03:58:52+00:00"
---

# A light rod of length \(L\) is attached to a frictionless pivot at one end. A small object of mass \(M\) is fixed to the rod at a distance \(d\) from the pivot, where \(d < L\). A constant force of magnitude \(F\) is applied to the free end of the rod, and the force is always maintained in a direction perpendicular to the rod. The rod and object are initially at rest. What is the magnitude of the angular acceleration \(\alpha\) of the rod-object system immediately after the force is applied?

A light rod of length \(L\) is attached to a frictionless pivot at one end. A small object of mass \(M\) is fixed to the rod at a distance \(d\) from the pivot, where \(d < L\). A constant force of magnitude \(F\) is applied to the free end of the rod, and the force is always maintained in a direction perpendicular to the rod. The rod and object are initially at rest. What is the magnitude of the angular acceleration \(\alpha\) of the rod-object system immediately after the force is applied?

![A thin horizontal rod of length L is shown. The left end is attached to a circular pivot point. A small solid circle representing mass M is attached to the rod at a distance d from the pivot. An arrow representing force F points vertically upward at the rightmost tip of the rod (distance L from the pivot). The arrow is labeled F.](https://nerd-notes.com/wp-content/uploads/ubq-frq-generated/stem-fig-1-1777953532-Yz32M0.jpg)

- **A.** \(\alpha = \dfrac{FL}{Md^2}\)
- **B.** \(\alpha = \dfrac{Fd}{ML^2}\)
- **C.** \(\alpha = \dfrac{F}{Md}\)
- **D.** \(\alpha = \dfrac{F}{ML}\)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/113096/*